Page 1 of 2 12 LastLast
Results 1 to 10 of 19

Thread: Unable to change brightness in Lenovo B570 laptop

  1. #1
    Join Date
    Jan 2010
    Beans
    13
    Distro
    Kubuntu 13.10 Saucy Salamander

    Unhappy Unable to change brightness in Lenovo B570 laptop

    Brightness adjustment keys [Fn] + [⇑]/[⇓] have no effect (although they are recognized by the environment), and I can't change the brightness using GUI tools as well. This seems like a problem in Linux itself, not the desktop environment.

    I can change the brightness in Windows OS, so it's not some kind of hardware fault.

    Details:
    Lenovo B570 (Model Name: 20093)
    Integrated Intel HD graphics card
    Kubuntu 11.04 (Linux 2.6.38-10-generic, KDE 4.7.0), everything up to date
    No proprietary graphics drivers (only Wi-Fi one)

    What I've tried:

    • Edit /etc/default/grubGRUB_CMDLINE_LINUX_DEFAULT: acpi_osi=Linux, acpi_backlight=vendor, nomodeset. And yes, I did update-grub
    • Edit /etc/X11/xorg.conf (no such file, even after sudo dpkg-reconfigure xserver-xorg)
    • Edit /proc/acpi/video/VGA/LCD/brightness (no such file)
    • sudo setpci -s 00:02.0 F4.B=## (no effect)
    • xbacklight -set ## ("No outputs have backlight property")

    How can I fix this issue?
    _________________________________________________

    This has been fixed in Ubuntu 11.10!
    Solution for older distributions
    Last edited by BlaXpirit; October 13th, 2011 at 07:01 PM.

  2. #2
    Join Date
    Jun 2005
    Location
    Toronto, Canada
    Beans
    Hidden!
    Distro
    Xubuntu 16.04 Xenial Xerus

    Re: Unable to change brightness in Lenovo B570 laptop

    I notice you've posted on a couple of other forums and unfortunately none of the usual solutions work. I would add one more possible thing you could try since you have an integrated intel video card - Kamal's custom kernel. (See: https://launchpad.net/~kamalmostafa/...l-mjgbacklight). I believe he is a kernel developer working on, among other things, improving support for intel-based video chips.

  3. #3
    Join Date
    Jan 2010
    Beans
    13
    Distro
    Kubuntu 13.10 Saucy Salamander

    Re: Unable to change brightness in Lenovo B570 laptop

    Quote Originally Posted by Kamal
    Code:
    lsmod | grep ^i915
    If no "i915" line appears, then this PPA will not be useful on your system.
    No line appeared

  4. #4
    Join Date
    Jun 2005
    Location
    Toronto, Canada
    Beans
    Hidden!
    Distro
    Xubuntu 16.04 Xenial Xerus

    Re: Unable to change brightness in Lenovo B570 laptop

    Then it looks like it won't work. Too bad. Out of curiosity, can you post back the full listing of
    Code:
    lsmod
    and
    Code:
    lspci -vnn | grep VGA -A 10
    and
    Code:
    ls /sys/class/backlight
    Also, are you currently booting with any kernel parameters?
    Code:
    dmesg | grep "Kernel command line"

  5. #5
    Join Date
    Jan 2010
    Beans
    13
    Distro
    Kubuntu 13.10 Saucy Salamander

    Re: Unable to change brightness in Lenovo B570 laptop

    WAIT A MINUTE!!!

    Talk about stupidity.
    I tried that line on the desktop PC, not the laptop.

    On laptop there actually was some output!

  6. #6
    Join Date
    Jun 2005
    Location
    Toronto, Canada
    Beans
    Hidden!
    Distro
    Xubuntu 16.04 Xenial Xerus

    Re: Unable to change brightness in Lenovo B570 laptop

    Here's something else to try.

    If
    Code:
    xrandr --prop | grep BACKLIGHT
    returns something, try:
    Code:
    xrandr --output LVDS --set BACKLIGHT <value>
    where <value> is one of the numbers in the range.

  7. #7
    Join Date
    Jan 2010
    Beans
    13
    Distro
    Kubuntu 13.10 Saucy Salamander

    Re: Unable to change brightness in Lenovo B570 laptop

    So I've installed the custom kernel. Brightness still doesn't work.

    Here are the listings you asked for. (After installing the kernel)

    xrandr --prop | grep BACKLIGHT yields no output.
    Last edited by BlaXpirit; August 19th, 2011 at 11:56 PM.

  8. #8
    Join Date
    Jun 2005
    Location
    Toronto, Canada
    Beans
    Hidden!
    Distro
    Xubuntu 16.04 Xenial Xerus

    Re: Unable to change brightness in Lenovo B570 laptop

    Did you try the new kernel with the acpi_backlight=vendor kernel parameter? Note: don't replace the work "vendor" with your vendor name - it should just say vendor.

  9. #9
    Join Date
    Jun 2005
    Location
    Toronto, Canada
    Beans
    Hidden!
    Distro
    Xubuntu 16.04 Xenial Xerus

    Re: Unable to change brightness in Lenovo B570 laptop

    And what does the following show:
    Code:
    cat /sys/class/backlight/intel_backlight/brightness
    Code:
    cat /sys/class/backlight/intel_backlight/max_brightness
    Code:
    cat /sys/class/backlight/intel_backlight/actual_brightness
    Then try something like:
    Code:
    echo 5 | sudo tee /sys/class/backlight/intel_backlight/brightness
    If still nothing, change back to the original kernel and what does the following show:
    Code:
    ls /sys/class/backlight

  10. #10
    Join Date
    Jan 2010
    Beans
    13
    Distro
    Kubuntu 13.10 Saucy Salamander

    Smile Re: Unable to change brightness in Lenovo B570 laptop

    Quote Originally Posted by Toz View Post
    Did you try the new kernel with the acpi_backlight=vendor kernel parameter?
    The kernel's page says the parameter isn't needed.

    Quote Originally Posted by Toz View Post
    echo 5 | sudo tee /sys/class/backlight/intel_backlight/brightness
    THIS WORKED! The screen became entirely black, because, as I later found out, max_brightness is 976! A reboot saved me from the black screen, so, unfortunately, the brightness setting is reset after reboots.

    By the way, without the kernel, there's nothing in /sys/class/backlight, even with acpi_backlight=vendor

    Now, how can I make some integration with the system? Particularly, KDE desktop.
    xbacklight probably tries to use the same thing (is it called interface?) as the system, so it doesn't work.
    If nothing can be done, I could make some scripts to read and write that brightness file, but it would need sudo all the time
    Last edited by BlaXpirit; August 20th, 2011 at 10:32 AM.

Page 1 of 2 12 LastLast

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •